CNGS and North Area Operation. Edda Gschwendtner, AB/ATB/SBA

Transcription

1 CNGS and North Area Operation Edda Gschwendtner, AB/ATB/SBA

2 North Area Introduction Outline 2 Particle production Wobbling Secondary/tertiary beam line Access issues Operational aspects Beam lines with long-lasting Experiments M2, Compass P42, K12, NA62 CNGS

3 The CERN Secondary Beam Line Complex 3 SPS North Area Three experimental halls : EHN1, EHN2, ECN3, 3 service buildings 7 beam lines ; ~1000 equipment installed ; total length 5.8 km ~2000 users / year performing experiments and tests ; frequent changes of beam configuration and settings

4 The CERN Secondary Beam Line Complex 4 PS East Area 5 beam lines ; ~120 equipment installed ; total length 300m ~300 users / year performing experiments and tests

5 The CERN Secondary Beam Line Complex CERN Neutrinos Gran Sasso, CNGS 1 beam line ; ~50 equipment installed ; total length 1 (+732) km LNGS experiments: OPERA and ICARUS 5

6 General 6 The SPS North Area originally designed to house long-lasting experiments demands for high quality of beams: high intensity, high energy, high resolution In recent years most of the users are tests LHC detectors with permanent or semi-permanent BIG installations several shorter-term users from astro-particle experiments and linear colliders The test users have very different requirements: scan full energy range ; typically [10, 300] GeV/c with sometimes increased precision (linearity) requirements use beams of all particle types (electrons, pions, protons, muons) with as good as possible separation and identification sometimes request high (or very high) rates all that during the few (or even one!) week(s) of their allocated time! Rapidly changing environment, quite demanding on beam conditions and tunes, often inexperienced users!

7 7 The North Experimental Areas at the SPS SPS (400 GeV/c) Extraction North + beam transport (TT20) Splitters + beam transport three p beams (400 GeV/c) in TCC2 The proton beam (400 GeV/c) from SPS is slowly extracted to the North Area at LSS2 The extracted beam is transported in the TT20 tunnel 11% slope to arrive into TCC2 then horizontal ; ~10m underground The primary proton beam is split in three parts directed towards to the North Area primary targets: T2, T4 and T6

8 North Area 8 The SPS North Area Beams The three proton beams are directed onto the primary targets: T2 H2 and H4 beam lines T4 H6, H8, and P0 beam lines T6 M2 beam line Experimental Areas: ECN3: underground experimental hall, transports the primary proton beam with high intensity to T10, from there high intensity secondary beam to the experiment in ECN3. (P42/K12) EHN2: surface experimental hall, receives the intense secondary beams or intense muon beam (COMPASS) EHN1: surface experimental hall, can receive secondary beams and/or attenuated primary proton beams (H4, H8)

9 The EHN1 Beams 9 Target T2 T4 Beam H2 H4 H6 H8 Characteristics High-energy, high-resolution secondary beam. Alternatively can be used to transport: attenuated primary beam of protons, electrons from γ-conversion, polarized protons for Λ decay, enriched low-intensity beam of anti-protons, or K + Main parameters: P max = 400 (450) GeV/c, Acc.=1.5 μsr, Δp/p max = ±2.0 % High-energy, high-resolution secondary beam. Alternatively can be used to transport: primary protons, electrons from γ-conversion, polarized protons for Λ decay, enriched low-intensity beam of anti-protons, or K + Main parameters: P max = 330 (450) GeV/c, Acc.=1.5 μsr, Δp/p max = ±1.4 % High-energy secondary beam. Main parameters: P max = 280 GeV/c, Acc.= 2.0 μsr, Δp/p max = ±1.5 % High-energy, high-resolution secondary beam. Alternatively can be used to transport an attenuated primary proton beam Main parameters: P max = 400(450) GeV/c, Acc.= 2.5 μsr, Δp/p max = ±1.5 %

10 Targets 10 T6 target (M2, COMPASS) T4 target (H6, H8, P0) T2 target (H2, H4) Wobbling magnets

11 The target heads Targets T2 target Position H (mm) V (mm) L (mm) Material 0 EMPTY Be Be Be Be Be Beam position monitors TBIU (upstream), TBID (downstream) <x> = -0.2 mm <y> = -0.4 mm 11 Position T4 target H (mm) V (mm) L (mm) EMPTY Material Be Be Be Be Pb mounted on same girder as the target head for better alignment beam steering onto the target using BSM located ~30m upstream of the target

12 Particle Production 12 Particle production inside the primary target Primary p beam (400 GeV/c) Target Development of hadronic shower Secondary particles ( 400 GeV/c) Protons : remnant of the incoming primary beams the target actually serves as attenuator Some emittance blow-up ~40% of the initial incoming intensity of the beam Attenuated proton beam Pions (hadrons) : produced in hadronic interactions Typical scale: interaction length (λ int ) Electrons : produced in electromagnetic processes Typical length scale : radiation length (X 0 ) Muons : produced in the decay of pions At the target and also along the beam line

13 Particle Production 13 Target material and length The proton intensity on each target can go up to protons/pulse limited by target and TAX absorber construction (i.e. cooling, etc.) The material with largest ratio: X o /λ int is preferred Beryllium Increasing the target length: more production but also more re-absorption lower the energy of the outgoing particles Optimal choice ~ 1 interaction length

14 Particle Production 14 Muon beam Muon beams are formed by the decay of pions (π +, or π ) Decay kinematics: At the pion center of mass system: p E * * 2 mπ m = 2 mπ 2 mπ + m = 2 m π 2 μ At the laboratory frame boost * * E μ = γπ E + βπ p 2 μ Limiting cases: = 30 MeV = 110 cosϑ = + 1 E cosϑ = 1 E MeV ( * cosϑ ) max min c c = 1.0 E π = 0.57 E π ν θ Conclusion: the muon beam energy is in the interval [0.57,1.0] of the initial pion beam energy μ (p *, E * ) E 0.57 μ 1.0 E π μ

15 How to Increase Flexibility with a Target Station? Produce several secondary beams from the same target when the primary beam hits the target: all particles are produced in a large variety of angles and energies the most energetic particles are in forward direction 15 SOLUTION: Wobbling: hit the target under variable angle But be aware: The very intense primary proton beam has to be dumped in a controlled way The secondary beams of the chosen momentum: into the directions foreseen by the beam geometry (i.e. inside the vacuum tube of each beam line)

16 Target Station Wobbling - General 16 0-order approximation: SPS protons Target TAX B1 single secondary or primary beam fixed production angle 1st -order approximation: TAX B1 two secondary beams SPS protons Target one could be the primary beam fixed production angles 2nd -order approximation: TAX B1 B1 two secondary beams Target one could be the primary beam SPS protons variable production angles B1

17 T4 Wobbling Example 17 P0 protons, H8 +180GeV, H6

18 T4 Wobbling Example 18 P0 protons, H8, H6 secondary beam

19 Wobbling Survey and Changes 19 Safety - Survey Survey current in the wobbling magnets Survey position of the TBIU, TBID monitors automatically done A program called WOBSU should be running continuously Manual INHIBIT signal set in CCC for planned wobbling changes. Wobbling Changes: Initiated by the EA physicist (upon the user requests) Discussed in the EATC / Monday meetings documented in the minutes Settings file prepared and communicated by the EA physicist Described in EA Wikipage Performed by the operators on the agreed time re-tuning of the the beam lines after the wobbling changes is often required

20 Secondary/Tertiary Beam

21 How to Increase Flexibility for Beam Energy and Particle Type? Reminder: Secondary beams: transport particles directly produced in the primary targets energy and polarity depending on the wobbling setting 21 Target wobbling : advantages: several beams per target are available flexibility of production angle and secondary beam energy drawback: introduces coupling between beams: e.g. P0 + H8 + H6, H2 + H4 changes are difficult to agree and schedule but the users (in particular the LHC detector calibration tests) demand a frequent change of beam energy and particle type solution: TERTIARY BEAMS

22 Tertiary Beams - Introduction 22 Allows more flexibility (independence) of the users in different beam lines keep longer periods with the same wobbling setting use mainly the filter mode optics Produced in two distinct ways: H2, H4, H6, H8: use a second target (filter) H2, H4: from the conversion or decay of secondary neutral particles

23 Secondary Beams - Reminder 23 Basic beam design momentum selection in the vertical plane two sets of bends Upstream BENDs between the primary target and the momentum acceptance collimator Downstream BENDs the main spectrometer of the beam momentum definition

24 H6 & H8 Beam Lines 24 View of the H8 and H6 beam lines in TT81 tunnel.

25 Tertiary Beams - H6, H8 25 Target (filter) after the upstream bends beam line tuned for two energies E1 (high energy) : from the primary target until the filter E2 (< E1) : from the filter until the experiment tertiary beams have typically lower rates acceptance collimators wide open XCON fine positioning filter/converter

26 Tertiary Beams - H6, H8 26 choice of target material enhance/select different particles Material Beryllium Copper Lead X o (cm) Λ int (cm) X o /λ int Mixed beam Hadrons Electrons

27 Tertiary Beams - H2, H4 27 Bend B3 of the wobbling as sweeping magnet charged particles are absorbed in the TAX neutral particles go through and hit the converter note: neutral particles can have zero or non zero production angle converter γ on Pb (Converter=lead): to produce electrons (e +, e - ) Converter=air (no converter) to let K 0, Λ 0, to decay K 0 π + + π - Λ 0 p + π - Bend B1: select charge and particle for the tertiary beam to the experiment

28 Electron Beams 28 Secondary beams Produced at the primary target rate goes down with energy increase Electron production: more with longer (Be-) targets e/pi ratio ~ proportional to target length With synchrotron radiation: separation from hadrons at high energies ( 120 GeV/c) mixed beams pion (hadron) contamination for lower energies user CEDAR or treshold Cherenkov counters for tagging Absolute electron/positron production rates from Be targets 1.E mm Tertiary beams H6, H8: use Pb as secondary target few mm, or ~1-2 radiation lengths (X0) radiation length: distance in matter where electrons loose ~1/e of their energy hadrons loose ~nothing e +- / sr pot 1.E+06 1.E mm 100 mm H2, H4: electrons from photon conversion high purity beams! 1.E+04 1.E P(GeV/c)

29 Hadron Beams 29 Secondary beams produced at the primary target positive sign beam a good fraction of the total hadron rate is protons Eliminate electron contamination using an absorber (~1-2 X 0 of Pb) in the beam Tertiary beams H6, H8: use secondary target of Cu, (CH) n ~1 interaction length λ I interaction length: characterizes the average longitudinal distribution of hadronic showers a high energy hadron has 1-1/e probability to interact within one λ I λ I >> X 0 for most of materials H2, H4: hadrons produced in the decay of neutral mesons Λ 0 p + π -, K 0 π + + π -

30 Muon Beams 30 Secondary beams Muons produced by the decay of pions muon momentum: % of the parent pion momentum For a pure muon beam for the experiment: close the last collimators of the beam line (out of beam axis) Momentum selected muons: closing the collimator upstream of the last bend of the line rule of thumb: muons in a 10 10cm 2 trigger represent ~1% of the hadron/pion flux there is another ~1% in a cone about 1 1m 2 around the beam axis 10 6 muons / cm 2 trigger 1.3 usv/h Tertiary beams Muon energy range % of the secondary beam momentum

31 Intensities in a secondary beam 31 primary proton beam x ppp Secondary beam < 10 8 ppp Tertiary beam < 10 4 ppp Primary Target Secondary Target

32 Ingredients for Transporting and Tuning Beam Type of Particles in Beam Targets Absorbers Converters Beam Steering and Focusing of Beam Bends Correction dipoles (Trims) Quads Clean-up of Beam Collimators (TAX, momentum, acceptance, cleaning collimators) Scrapers, MIBs Steering, Momentum Measurement, Particle Identification, Timing/Spill Scintillator MWPC (Analog Chamber) XDWC (Delay Wire Chamber) FISC Counter XCET Cedar EXPT (Experimental Scaler) Ionization Chamber 32

33 1. Dump collimators (TAX) 33 TAX stands for Target Attenuator experimental areas stop the primary beam (e.g. in case of access) define the beam acceptance or limit its rate (by attenuation) primary beam Target Acceptance defined by TAX 1.6 m long water-cooled table with Cu, Al and Fe blocks This table is motorised in the vertical plane some holes of different diameters are drilled contain cm of Beryllium (for attenuation) One position (+ 140 mm) is fully plugged (DUMP) The range of the movement is interlocked (EA safe Chain 9) TAX are also safety elements in the Access system

34 2. Momentum collimator 34 Normally located at a dispersive focus. Center of the gap should be at nominal beam axis. The aperture is proportional to the accepted momentum band, The rate is normally also proportional to the gap. However, ΔP/p cannot be smaller than the intrinsic resolution. Hence the need (in general) to have a rather sharp focus. 3. Acceptance collimator Located where the beam is large (ideally even parallel), Allows to define the angular aperture of the beam, Affects therefore the rate as well, however non-linearly. 4. Cleaning collimator A repetition of an earlier (acceptance) collimator. Cleans up particles scattered on the edge of the earlier collimator

35 Optics File - H6 Part1 Acceptance coll Sec. target 35 MWPC, Scint,.. collimators bends, quads trims T4 Horizontal plane 130m 250m Vertical plane Momentum coll T4

36 Optics File - H6 Part2 36 MWPC, Scint,.. collimators bends, quads trims Horizontal plane 410m 530m CERF H6A H6B Vertical plane

37 North Area Operational Aspects

38 Organization of EA Operations 38 EA experts: Setting up (commissioning) of secondary beam lines. They provide operational setting files. SPS operators handle the technical problems of the secondary beam lines. change beam conditions according to schedule using operational setting files

39 Operational Aspects General Goal: deliver good quality of beam to the experiment! sufficient rate, spot size, particle purity, Tuning the beam is required for each change energy, wobbling, user To first order, all beam lines are quite similar however there are some differences which need time to become familiar with Some users are quite experienced with their beam, and can do many things alone Time is important for you and the users there is always a limit to how good a beam can be; let the users decide 39

40 Operational Aspects Startup Beam line snapshot: status of magnets/files/wobbling settings status of collimators, target, absorber rates in few counters (start, middle, end of beam line) Start from an already prepared beam file by the EA physicists WIKI pages Be sure it corresponds to the present wobbling settings Be sure it can fulfill the user requirements typically users know their files, but better check it.. Treat each plane independently start with the vertical plane which is the most important to get the beam to the experimental hall Select your observation point a scintillator counter close to the end of the beam line 40

41 SPS-OP Wiki 41

42 ATB-SBA Wiki 42 wobbling file beam file Regularly updated new user new beam requirements

43 Operational Aspects Remarks 43 Switching beam files: secondary beams have high rates acceptance collimators closed tertiary beams have low rates acceptance collimators wide open therefore: switching from tertiary to secondary beam, load FIRST the collimators and then the magnets Consistent particle rates when following them along the beam line use as much as possible normalized rates: rate/pot monitor beam losses, be sure you are looking at the beam not at its halo For electron beam: electrons hate material! remove triggers or other detectors from the beam line, otherwise you may damage the whole beam line be careful when you try to measure/monitor things, you may disturb the users

44 CESAR - Equipment and Control 44 Equipments Magnets Collimators Scrapers TAXs TDXs, TDVs Obstacles (Targets, Converters, Absorbers, ) Pumpes (only reading) Scalers Scintillators Analog Wire Chambers (status+profiles) Delay Wire Chambers FISCs (status + fast & slow profiles) SEMs Doors Access command & diagnostic Files Management Mode analyze General Status Scan North Area Fix Display North Area Interlocks Login + Security

45 45 Menus + Toolbars Navigation equipment oriented Work area one per beam

46 Menus and Toolbars 46 Toolbars with shortcuts with the most useful actions Menus with same hierarchy as Nodal tree

47 File Handling 47 Choose a Beamfile Load the Beamfile

48 Actions 48 All Actions possible popup menu Actions possible the most important actions are always visible (when an equipment is selected)

49 49 Collimators Control

50 Beam Steering - Scans 50 Select Detector Select Steering Element Select Scan Range

51 Access System

52 Access System General 52 Beamline and Experimental Area classification Secondary beam areas EHN1 (H2, H4, H6, H8) EHN2 (P61/M2) access granted locally interlock system per beam line/area Primary beam areas TCC2 (north area targets) ECN3 (P0) same access rules as SPS machine and target zones The access system is used to prevent in-beam exposure for the personnel For EA two categories: Barracks and Experimental zones

53 Access System NA Beam Interlock 53 Proton extraction to the North is allowed only if the North Area is in SAFE mode North Area SAFE when ALL the corresponding Beam Lines are in safe mode Beam Line SAFE if - either the nominal beam energy is limited below the energy of primary protons ie. cannot transport primary protons or the beam intensity is limited by beam attenuators (TAX's or combination of TAX's and other beam elements)

54 Access System Safety Elements 54 Doors: allow access to the experimental areas and underground tunnels the main one (PPE) and at least one emergency escape door (PPX, PPG) if a door is left open more than 1min switches automatically to free state Free, key access, closed (beam on/off) Dumps: motorized dumps to separate experimental areas in the same beam line attached to the interlock chain of the downstream area Before moving a dump the beam must be stopped to avoid spraying particles as the edge of the dump crosses the beam TAX: motorized blocks dumps with holes to attenuate or dump the beam two motors (XTAXxxxyyy) per beam Massive blocks of material (Al-Cu-Fe), 3.2m long\ Movement split in ranges: small (primary beam), medium, large (sec. beam) Magnets: stop the transport of a beam; ( champ null detector, current limit, interlock) Equipment: has to be present and in a given configuration H8 micro-collimator Special case: radiation monitors can stop the beam if above threshold, but not included in the access system Status information available on the control room

55 55 Interlock chains - North Area

56 Access System - Example 56 PPE168 H8B Large area with four doors and a search point Big and complicated detector installations Radioactive sources, gas distribution (including flammable) PPX168 Search point PPG168 PAX monitor XTDV dump Magnet interlock Beam dump PPX168 PPE168

57 Access System - Doors 57 PPExxx Door keys door and area status and control panel door handle

58 58 Access System Door Status and Control Display Displays the status of the PPE doors Allows monitoring and control of their state The doors can be in one of the following states: FREE No access control KEY ACCESS Access with key Limited number of people CLOSED Beam present

59 Access System Interlock Chain Status Hardware system to define a status of a beam line Hierarchical organization Interlock signal based on information from at least two safety elements 59 The chains can be: SAFE If all the elements in the chain are in the SAFE state it means we can have access to the area or UNSAFE If any of the elements in the chain is in UNSAFE state we can t have access the beam is present

60 Access System SW Chains/Matrices 60 like an Access Sequencer Hardware layout is reproduced in CESAR system Should correspond to the actual hardware configuration matrices describing the configuration of each interlock chain Used to facilitate the users/operators avoid mistakes that can cause access alarms fast help and monitor of the access system however Intended for high-level commands/programs direct calls to the hardware (ie. move a TAX or XTDV) may still be possible Software interlocks not considered as SAFE Note: Hardware for the interlock system maintained by M.Grill (ST/MA) Annual inspection before SPS startup

61 Request Access in CESAR 61

62 Access System Manual Veto To veto an interlock chain of a beam line Key blocks beam in an exp. area regardless the status of the existing safety elements of the chain 62 Normal status of all exp. area chains during shutdown Must be set when work foreseen that can modify the status of an exp. area Can ONLY be lifted with the agreement (signature) of the EA physicist. The EA physicist must patrol the exp. area before signing to lift the Manual Veto verify that its perimeter is correctly closed the safety elements (dumps, doors, magnets) are present and functional i.e. must verify that the access system can function correctly

63 Access System Search & Secure Procedure 63 Needed in order to switch from Free to Key access The search is conducted by the search leader normally the GLIMOS of the experiment and other authorized person(s) The defined procedure should be rigorously followed

64 Search Zone / Rearm Doors 64 Procedure: 1. Ask all the persons present in the area to exit and close all the doors (PPE, PPX, PPG) 2. Verify that all fences and blocks defining the perimeter of the area are in place 3. Remove all ladders or any other equipment can be used by people to climb over the fences 4. Go to the PPE door and call the PCR to switch it from Free Access to Key Access 5. Leave one person at the PPE door and start the search. All persons entering the area must take a key. Audible devices can be used during the search to warn people. Take your time and look carefully everywhere 6. If there is a Search Box you must re-arm it although there is a time-out to do so, don t rush! it is more to force you to look into that area not just to turn the key! 7. Return all the keys to the PPE door and press the End of Access button

65 65 Access System Changes to Access System Initiated and under the responsibility of the EA physicist New conditions from users, modifications in the beam line or exp. area All the parties involved are consulted and agree EA physicist takes care EA and BI beam line experts access system experts, ST/MA (M. Grill) TIS/RP and AB/RSO All modifications: discussed in the EATC meetings and documented in the minutes 1 st meeting of the year: summary of all modifications during the shutdown during operation, in the meeting before the SPS period concerned

66 RP Central data acquisition system 66 All installed radiation alarm monitors can be read remotely Data are stored in a database for further retrieval The parameters for each monitor are accessible can only be set/modified by authorized persons (TIS/RP)

67 RP Central data acquisition system 67 Baracks: level A: 3 μsv/h level B: 6 μsv/h Zone: level A: 15 μsv/h level B: 30 μsv/h

68 68 Beam Lines with Long-Lasting Experiments

69 69 M2 (COMPASS)

70 70 9 x 1.1 m Beryllium to stop the hadrons 172 ± 17 GeV/c 160 ± 6 GeV/c

71 M2 Beam Line for COMPASS km long beam line that serves the COMPASS experiment (only user) produced from the T6 primary target Operated in three basic modes: 1. High-intensity muon beam in the momentum range 60 to 190 GeV/c Typically muons per pulse from ppp on T6 So far the main mode. 2. High-intensity, high energy hadron beam, typically ±190 GeV/c Typically hadrons per spill, from ppp on T6 (tbc) 3. Low-intensity low-energy low-quality tertiary electron calibration beam Typically few 10 3 electrons per pulse of up to 40 GeV/c In 2008 the beam will mainly be operated as a hadron beam. Some short (~1 week) runs with electrons and muons are foreseen as well.

72 The Hadron Mode Simple secondary hadron beam Never yet been fine-tuned so far New improved optics version is prepared Will be commissioned in 2008 Once commissioned, operation conditions should be stable Documented on Wiki page, elogbook, beamfiles 72 The request is for +190 GeV/c ppp -190 GeV/c ppp both assuming a long flat top operation Rel.Flux The intensity is controlled via: COLL-1 H = COLL-3 H COLL-2 V = COLL-4 V T6 primary target head All absorbers are OUT also momentum slit vertical acceptance 0, 40, 100, 200, 500 mm T6 length

73 M2 Specials T6 target head: under user control BEND-6: momentum defining bend never change its value! Bends 10 and 11: main spectrometers of COMPASS. Do not switch them off without informing / consulting COMPASS (except in case of emergencies or force majeure ) The SM1+SM2 interlock: In case of a trip (or wrong current) in spectrometer magnets SM1&SM2 Interlock puts Bends 4 on delestage Avoids that beam hits sensitive parts of detector Interlock only be disabled by the experiment! SCRAPERS and MIBs are special magnets: provide ~ 0 field on axis and a toroidal field outside the beam aperture to clean muon halo. Do not touch scraper positions without good reason! 73

74 Two CEDAR counters will be commissioned and used. Special status and Scan GUIs have been developed: 74

75 Other Modes of M2 75 Electron Mode -100GeV/c upt to Q20, -40 GeV/c or lower after Q20 5mm lead converter ( electron target is IN) downgrades energy of electrons Muon Mode Beam energy downstream of hadron absorber ~8% lower than upstream At least 7 absorber modules are IN to stop all hadrons Scrapers and MIBs are important in that mode Changes between different modes: under ATB/SBA control or by instructed experts in the experiment. Documented in Wiki pages

76 Summary of M2 Beam Modes 76 See the M2 User Guide on the ATB-SBA web page for more details

77 77 P42, K12

78 The P42 + K12 beam lines for NA62 From T4 primary target to NA62 experiment in ECN3 2 parts P42 primary proton beam from T4 to T10 Target (~840m) K12 beam from T10 to the experiment (~260m) 78 P42 settings: Rather stable Only fine steering onto the 2mm diameter T10 target K12 settings: Frequent changes But: P42 and K12 only starts operation on 11 th September 2008! Physics Straw R&D RICH R&D

79 P42 Specials 79 Magnet currents: tuned and kept updated in P42 beam file Only Trims 9 and 10 regularly tuned to steer onto T10 (wobbling!) High intensities use of collimators forbidden! Control of T10 flux only possible by Changing TAX hole (=position) in the P42 TAXes (only discrete changes) Changing intensity onto T4 (any values, but tedious) Changing T4 target head (affects H6, H8- needs EA physicists) Intensity is high (1.5 10E12 on T10 target) currents of main bends in P42 and some currents in K12 are monitored by P0-SURVEY Cooling of the T10 target and TAX are monitored by DUMP CONTROL Access to ECN3 and galleries requires closure of P6 TAXes Never disable P0 survey or DUMP control without prior agreement of the responsible EA physicist!

80 P42 Trim Scans 80 P42-TRIM9 scan P42-TRIM10 scan

81 P42, K12 P0Survey Via EA / P0Survey menu, only in P42 workspace: 81 DMPC tab Note: Status TABs opens window where magnets in fault are highlighted in red Possibility to reset alarm, once the problem has been fixed

82 P42, K12 P0Survey 82 Config tab Choose surveillance reference file corresponding to beam file in use To activate new survey references Normally only changed by EA physicists

83 The K12 beam: (Kaon physics mode) 83

84 Operation Modes of K12 Beam Line: 84 K + or K - or simultaneous K + + K - beams (typically ±75 GeV/c) This is the typical condition for physics operation Two achromats with momentum selection in K12 TAX Muon sweeping with Bend3 ( filled with Iron) and scrapers Muon beams Dump the beam from T10 in the K12 TAX Switch muons sweepers, quadrupoles, trims and 2 nd achromat off Low energy secondary beams for straw detectors 40 GeV selected instead of 75 GeV, deflected away from beam (by 15 cm!) axis with Trim-3 (as in 2007) Low-energy secondary PARALLEL beams for RICH prototype typically around 30 GeV. Special beam optics. NEW FOR Changes between these modes are done by EA physicist They involve beam files, K12 TAX positions, P0-survey

85 K12 Specials: The K12 TAX have two race-track slits: can be offset to define one or two momentum slits one hole on the central axis Bends 6 and 7 control the two 200 mm K12-TAX1 coupled pairs of coils of the MNP33 spectrometer. operated only via a special program EA MNP33 in the K12 beam Three special XCLD collimators allow to define the angular acceptance of the beam line. solid blocks with a fixed dimension hole. can be moved IN and OUT of the beam. 40 mm K12-TAX2 When IN, they can be positioned finely in both planes (range ±4 mm) 85 Please do not move without consulting the EA physicist!

86 Access to K12 86 Access to ECN3 cuts 4 TAX and 3 rectifiers. reset of P0-survey necessary after end of access. Normally done automatically by the access program The technical gallery G300 access requires small range on P42-TAX2 Monitored by a EA-SIS program. If the position or range changes during access, P42-TAX2 is closed! If P42-TAX2 does not open beyond +44 mm, the range is blocked most likely due to the user not having pushed End of Access button after an access to G300 Change TAX to medium or large range once the G300 access ended More details under K12 from the ATB-SBA home page and in the Wiki pages.

87 87 CNGS

88 CNGS Project 88 CNGS (CERN Neutrino Gran Sasso) A long base-line neutrino beam facility (732km) send ν μ beam produced at CERN detect ν τ appearance in OPERA experiment at Gran Sasso If neutrinos have mass... ν e ν μ ν τ neutrino oscillation direct proof of ν μ - ν τ oscillation (appearance experiment)

89 OPERA 89 Spectrometer 11 th January 2008: bricks (out of ) are produced Production is stabilized at a rate of 3 drums/day (700 bricks). Finished by 10 th June Target tracker Veto brick 8.3kg

90 OPERA 90 Brick Manipulator System, BMS

91 First CNGS Neutrino Interaction inside an OPERA Brick, 2 nd October Tue, 2 Oct, 17:04:25 ν μ CC interaction Muon 7GeV/c Event display

92 CNGS Challenges 92 High Intensity, High Energy Proton Beam (2 x p/cycle) Proton Beam: Tune!!! Induced radioactivity In components, shielding, fluids, etc Intervention on equipment impossible Remote handling by overhead crane Replace broken equipment, no repair Human intervention only after long cooling time Design of equipment: compromise E.g. horn inner conductor: for neutrino yield: thin tube, for reliability: thick tube Beam parameters Nominal energy [GeV] # extractions per cycle Batch length[μs] # of bunches per pulse Intensity per extraction [10 13 p] Nominal CNGS beam 2 separated by 50 ms 2100 Intense Short Beam Pulses, Small Beam sizes at 0.5 mm Beam Spot (within ±0.5mm of target) 400 GeV [mm] Proton Beam: Interlock!!! Thermo mechanical shocks by energy deposition (designing target rods, thin windows, etc ) most challenging zone: Target Chamber (target horn reflector)

93 93 SPS protons LHC pions kaons CNGS muons neutrinos Neutrinos to Gran Sasso

94 CNGS Layout 94 pit 1 pit 2 p + C (interactions) π +, K + (decay in flight) μ + + ν μ Muon detectors are monitoring: muon intensity muon beam profile shape & centre Muon energy filter due to 67m rock in between pit 1 and pit 2. Muon intensity: Up to ~8x10 7 per cm 2 and 10.5µs

95 Target Magazine 95 proton beam

96 96 Horn Unit HORN System REFL. System Load Peak current ka Pulse duration ms Water flow for delta T=5C l/min Installation of the horn in the target chamber Pressure bar

97 Muon Monitors 97 60cm LHC type Beam Loss Monitors Stainless steel cylinder Al electrodes, 0.5cm separation N 2 gas filling 2x41 fixed monitors + 2x1 movable 270cm 11.25cm Online feedback to neutrino beam quality (sensitivity to any misalignment of beam vs. target vs. horn, horn/reflector currents, etc )

98 CNGS Layout Radiation safe area for electronics Parasitic LHC Radiation Test Facility TSG4 Service Gallery TCV4 Proton Beam Line target horn He tube 1 reflector He tube 2 decay tube Target Chamber electronics equipment

99 99 New Shielding Layout Radiation safe area Radiation reduction at order of ~10 4

100 CNGS Operational Aspects

101 CNGS Operational Aspects Static operation : shoot the beam in the middle of the target. the beam must hit the target very accurately!! target resistance and to protect other equipment! 101 Steering is very reliable Simple but dangerous (lot of interlocks) Main operator s effort is on keeping the beam quality in the ring. Especially with frequent SC-changes. Need of EA specialist for beam-monitors-target-horn alignment. Heavy involvement of RP in access procedures.

102 Primary Beam Line 102 Beam losses in TT40 and in TT41. Losses above threshold trigger beam interlock. In TT40 > 20 mgray (BLM behind the TED >100 mgray). In TT41 > 5 mgray on all monitors (except first one- sees losses from TED). Horizontal and vertical beam trajectory. Positions are interlocked. Always steer to the reference trajectory. More details on Primary Beam Operation: see SPS/OP Wikipage!! J. Wenningers talk

103 Horn/Reflector Control 103 Horn, 150kA Important!!! SW of horn/reflector only allows control when CNGS user is active. Without CNGS user in the SC, one cannot switch the horn/reflector ON and OFF Reflector, 180kA

104 Login; operator Acknowledge alarms 104 Oxygen content in the Helium Tubes asdfe ON or Access Veto Neutrino or Antineutrinos

105 105 asdfe Cooling water pumps ON (green)

106 Muon Monitor on-line display 106 E muon > 20GeV E muon > 50GeV pit 1, horizontal pit 2, horizontal pit 1, vertical pit 2, vertical Pit 1 Pit 2

107 CNGS Fixed Display Muon Profiles Good! 107 Pit 1 horizontal Pit 1 vertical Pit 2 horizontal Pit 2 vertical

108 CNGS Fixed Display Muon Profiles Medium 108 Pit 1 horizontal Pit 1 vertical Pit 2 horizontal Pit 2 vertical

109 CNGS Fixed Display Muon Profiles Bad! 109 Pit 1 horizontal Pit 1 vertical Pit 2 horizontal Pit 2 vertical

110 CNGS Fixed Display for Secondary Beam 110 The muon profiles for both pits (pit 1 and pit2), horizontal and vertical Multiplicity Number of charged particles downstream the target per proton hitting the target Target status green: everything is ok red: interlocks or temperature warning or error with target both in position 'in beam' or 'out of beam'. Target in beam status green: (any) target is in beam red: target is out of beam Horn (Reflector) status green: horn is 'ON'. red: horn is 'OFF' or 'Standby' or any kind of error message. Shutter status green: shutter is open, i.e. beam mode. red: shutter is moving or closed, i.e. access mode.

111 CNGS Fixed Display for Secondary Beam 111 Beam status word 0 : beam is ok, nominal conditions, no error flag is set. 1 : Minor error conditions with respect to nominal beam values. (e.g. Ihorn off by 1-5% or muon centroid pit 1 (pit 2) shifted by 4-10cm (1-5cm) ) 2 : Major beam problem. (e.g. Ihorn off by 5% or muon centroid pit 1 (pit 2) shifted by more than 10cm (5cm) ) 3 : No beam for this extraction (intensity 25 times lower than nominal) 4 : Beam tests. Set by the operator. 20 : in case of lost data of any of the above parameters. In case of lost data of any of the above parameters a value of 10 is added to the beam status word.

112 CNGS Access 112 Documents on modified CNGS access system 2008: For any access to CNGS tunnels and caverns: Access via the CNGS access point in ECA4. Operator in CCC launches access procedure: Beam off Shutter must be closed!!! Plugs PPP TSG4 and PPP TSG41 must be open!!! Horn/Reflector switched off and grounded All safety elements of chain 6 must be safe

113 CNGS Access 113 Radiation-Veto must be removed by the RP technician RP technician remotely reads monitors providing residual activity and air quality decides on waiting time. After waiting time (usually 2 hours) and remanent dose is ok: Ventilation system changed from beam mode to access mode CCC operator calls TS/CV operation section After waiting time (usually 4 hours!) RP technician removes the Radiation Veto (switching a contact locked by a key at the access point in ECA4) The RP technician makes a dose map of the area. If dose is acceptable, user gets a key in the CNGS access point Access of the user together with the RP technician Dose planning mandatory for any interventions

114 Operational Aspects Continuous radiation monitoring of prompt radiation, released radioactivity and induced radioactivity Ramses detectors: warning, interlocks Stray radiation monitoring stations: gamma & neutron monitors Induced activity monitors Ventilation monitoring station: gas monitor & aerosol sampler Hand & foot monitor Tools & material controller ARCON system Remote radiation survey on overhead crane!!! RadMon Radiation Monitors!!! 114

115 Shutter 115 Decay tube is closed with 3mm Titanium window Must be protected by a shutter when access Hardware Interlocked!!!

116 Further Information 116 Experimental Areas: General: EA-Wiki: SPS Wiki: CNGS: General: Training, etc : Operation aspects primary beam: Operation aspects secondary beam: